The cardinal said in a statement issued Monday that he will not attend because he doesn't want media attention focused on him during the important session in Rome.

The Vatican confirmed O'Brien had resigned as archbishop of Saint Andrews and Edinburgh. It was accepted under the code of canon law for reasons of O'Brien's age; he turns 75 -- the normal retirement age for bishops -- on March 17.

O'Brien has said he is contesting allegations in a British newspaper that three priests and a former priest have filed complaints to the Vatican alleging that the cardinal acted inappropriately with them.

The one-sentence Vatican statement made no reference to the allegations.